Control system



T. U. WHITE CONTROL SYSTEM April 25, 1933.

Filed June 23. 1925 2 Sheets-Sheet 1 QSE@ Q E IN'VENTOR Thomas U. Wfl/'fe WITNESSES: //f Xdir# ATTORNEY vBY April 25, 1933. T U WHITE 1,905,256

CONTROL SYSTEM Filed June 23. i925 2 Sheets-Sheet 2 t l ENToR Md Thomas 0. W/e

MM /WJMA/ ATTORNEY Patented Apr. 25, 1933 THOMAS U. WHITn, or PITTSBURGH, PENNSYLVANIA, y.assicrNoa To WEsTINeHoUsE NT ori-ICE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA CONTROL Application led June 23,

My invention relates, in general, to supervisory control systems, and particularly to systems for supervising and controlling remotely-disposed electrical apparatus from a central station.

One object of my invention is to provide means whereby it is possible to supervise and control electrical apparatus in a large number of remotely-disposed stations over a single pairof Wires.

Another object of my invention is to provide means for selecting any one of the stations and for locking out the remaining stations.

Another obj'ect of my invention is to provide means for selecting the various electrical apparatus in the different stations so that Vthe same code may be utilized for such selection in all stations Without interference with the apparatus in any of the other stations.

Another object of my invention is to provide means for indicating to the dispatcher at the central station, the selection of the desired station, that is, to give an answer-back signa-l indicative of such selection as often as desired.

Another object of my invention is to provide means for selecting the various remotelydisposed electrical equipment and obtaining a signal indicative of the condition thereof Without causing any change in the selecting apparatus. l

A further object of my invention is to provide means for operating any one of the apparatus units in any oneof the remote stations and preventing the apparatus unit being again operated even though automatic apparatus in the station functions to immediately restore the device to its inoperative condition.

A still further object ofmy invention is to provide means for indicating, at the centralstation, the occurrence of a certain detlnite operation or number of operations in any one of the remote stations.

There are other objectsl of the invention which, together With the foregoing, Will be described inthe detailed specicatfon which is to follow. f

In practicing my invention, I provide a SYSTEM 1995. serial No. 39,069.

indicative of the -sta-tion selection' and the condition of the desired unit. y

Referring nowto the drawings, Figures 1 and 2 together` constitute a diagrammatic illustra-tion' ofa system in Whichsuicient apparatusv and circuits are shown to enable my invention tobe rea ily explained. and understood. f f Y Withinthe dotted figure, in the upper lefthand portion of Fig. 1, is shown a telephone substation A, which may be of any Wellknown local battery type, comprising a ringer 108, a receiver 102, an induction coil 100, a transmitter 101 and a generator 103 that may be employed for signalling various other substations, such as A-l, by any Well-known By the e0r Y ringing code.` This telephone substation is provided With keys K and K-1 which may be of any Well-known locking type.

A calling device 104 is also provided-for controlling the operation of the selectingdevices at the various stations that are connected to the trunk line, comprising the conductors 105 and 106. A loud-speaking device 1.10 is connected to the conductors 105 and 106 at the receiving station. This device may be of any Well-known type 'and is provided for the purpose of enabling the dispatcherv to hear the audible ansvver-back signals With-v l out having to'resort to the receiver 102.

Theremaining apparatus and circuits indicated in Figs. l and 2 are conventional diagrams of the equipment llocated at one of the remote stations. This apparatus comprises a selecting device S Which isa rotary switch of the usual type comprising Wipers 144 to 147, inclusive, each of Which is adapted to engage a set of twenty-five bank contacts.

The wipers are mounted upon a shaft which is adapted to be advanced by a motor or stepping magnet 143. The mechanical construction of this switch is similar to that shown in Clement Patent No. 1,107,153. Relays 135 to 142, inclusive, control the operation of the wipers 144 to 147, inclusive.

Another rotary switch S-l is provided at the distant station and is of the same mechanical construction as the rotary switch S.

This switch has four wipers 117 to 120, inclusive, that are adapted to be advanced by the operation of the stepping magnet 115.

The apparatus within the square 112 comprises an ordinary transmitter 125, an'induction coil 124, a'bell 126, a buzz-er 127 havingr a low tone and a buzzer 128 having a high tone. The transmitter 125 is mounted with respect to the bell 126 and `buzzers 127 and 128 so that the'indications given by Vthese buzzers affect the transmitter. Relays 111 to 11.6, inclusive, controlI the functioning of the answer-back device S-1. The `relays 200 to 206, inclusive, and 209 to 215, inclusive, are of the usual type and control the functioning o the selecting and answer-back equipmentin a manner that will appear. A circuit breaker of any well-known type is indicated at C. i

At `FS is indicated a gate switch that is adapted to be controlled Vby the opening of the gate ofthe water turbine, it being assumed that the station A--1 is a hydro-electric generating station. As is-well known,

., these stations are usually located along small streams tosupply energy toa power network. In a station of this kind, the selecting equipment disclosed is very desirable, inasmuch as it is necessary to reliably control the smallunit stations with a minimum of expense. As the gatey opening changes, a contact-making member 218 is moved to diierent contacts, such as 216 and 217.

A relay 219 is provided at each station and is operated by the automatic equipment. This relay may be energized when certain operations at the station occur by reason of the functioning of the automatic equipment. That is, it may be essential `for the dispatcher to know when the station is locked out. In this case, the locking out ot the station would bring about the energization of the relay 219. Relays 250,251, 253, 254 and 255 are associated with the circuit breaker C-1, and control its operation. v A local battery telephone is also located at the station A-1. This telephone comprisesV the usual transmitter 168, induction coil 148 and telephone receiver 169. A plurality of other stations, having apparatus similar to the station A-r-1, may be connected to the trunk line comprising the conductors 105 and 106.- The operation of the calling device 104 at the dispatchers otiice causes the selection of any one of the desired stations such for example as A-1, in a manner that will be eX- plained.

The number of stations that may be located along a single pair of conductors is limited only by the capacity of the selecting devices, such as S, and the number of operations that it is desiredto perform in each station. This will appear more fully in the subsequent description.

vHaving briefly described the apparatus shown inL the drawings, I will now explain its detailed operation. For this purpose., it

"will be assumed that the dispatcher desires to bring about the closure of the circuit interrupter C at the station A-l.

In order to select the station A-1, the dispatcher will operate the key K and will then operate the calling device l104 in accordance with the digit 2, as this'is the number assigned to this station. lVhen the key K is operated, ground is disconnected from the con ductor 105 and connected to conductor 106, and battery is disconnectedfrom the Conductor 106 and connected to the conductor At the stations along the trunk line comprising the conductors 105 and 106, polarized relays, such as 135, are bridged across these conductors. Normally, the armatures associated with these polarized relays are heldin engagement with their left-hand contact, as shown by the armature 148. However, when ground isconnected to the conductor 106 and battery to the conductor 105, the direction of current flow is reversed through these polarized relays and the armatures, such as 148, are operated into engagement with their right-hand contact members.

By the action of the armatures 148 in each station, a circuit is completed which will be traced in the drawing. It will beunderstood that this circuit in the stat-ion -A-l is typical of all the similar circuits in the various stations. K 1

A circuit extends from ground by way of armature 148 and its front right-hand contact and slow-release relay 139 to battery. The slow-release relay 139 is energized to remove ground from-the bank contacts accessible to the wiper 119 at armature153, to remove ground from the bank contacts accessibleto the wiper 147 at armature 155, to prepare locking circuits for the relays 140 and 141 at th-e front contact of this armature, and to place the line relay 136 across the trunk conductors 105 and 106 at armature 154. .As the line-relay 136 is placed in a bridge of the trunk conductors, this relay is energized.

A. circuit is now completed for the slowrelease relay 138 at armature 149. The slowf release relay 138 is energized to prepare a circuit for the slow-release relay 137 at armature 151, and to prepare a circuit for the motor magnet 143 at armature 152. y

Now, when the calling device 104 is oper- Y ated by the dispatcher at 'station.A, two interruptions are produced in the circuit of the line relays, suchv as 136, and these relays retract their armatures twice. i Upon the first retractionof the armature 149,the `circuit of the slow-releaserelay 138 is 4opened anda circuit iscompleted at armature 149 that extends from ground by way of said armature and its back contact, back contact and armature 157, armature 152 and its front contact, and stepping magnet 143 to battery. n A circuit in'multiplewith that above eX- tends by Way of armature 151- and slow-releasing relay 137 to battery. The sloW-releasino relay'137 is energized to open one point in the circuit to be traced later of .the relay 141 at armature 150. The stepping magnet 143 is operated to actuate its armature 165 and to adjust the associated pawl so as to advance the switch shaft, carrying the Wipers 144 to 147, inclusive, upon the deenergization. of the magnet 143. Y

l/Vheny the armature 149 is attracted, the circuit of the relay 137 is opened and the circuit of the slow-release relay 138 is completed. The magnet 143 is deenergized to cause the switch wipers 144 to 147, inclusive to be ad'- vanced vone stepinto engagement with their secondset of bank contacts. Upon the next deen'ergization of the'relay 136, another iinpulse of current Vis sent to the stepping magnet 143.` The stepping magnet 143 again operates to adjust its pawl. When the armature 149 is attracted, the circuit of the stepping magnet 143, as Well as the circuit of the slow-release relay 137, is completed. As a result of the operation of the magnet 143, the switch wipers 144 to 147, inclusive, are advanced another step into engagement with theirl second set of bank contacts.

. During the intermittent operation of the line relay 136, the slow-release relays 137 and 138 are held energized. However, as the operation of the calling device only causes two interruptions in the circuit of the line relay 136, after the second retraction ot' the armature 149, the circuit of the relay 137 is permanently opened.

After a short interval of time, the relay 137 is deenergized to complete a circuit eX- tending from ground by Way of armature 149 and its front contact, armature 150 and-its back contact, Wiper 146, third bank contact with which said Wiper is in engagement, norinally closed springs .controlled by armature 160, and relay 141 to battery. The relay 141 is energized to open one point in the circuit of the relay 140 at armature 159, to open its original energizing circuit to establish a locking circuit for itself at armature 160, and to complete a circuit for the relay 142 at armature 161.

The circuit for relay 142 is completed over 150 and its back contact, a-rmature l161 audits front contact, and relay 142 to battery. The relay 142 is energized to connect ground to Wiper 144 at armature 162,*to complete a circuit at armature 163 that extends from ground by Way of said armature and its front contact, and relay 111to battery, and to complete a circuitV at armature V164 that eX- tends from ground by way of front contact and saidarmatureconductor 195, armature 236. and its back contact, back contact and armature 239, and relay 211 to battery.

`The relay 111 is energized to complete a circuit for the transmitter 125 through the primary Winding of the induction coil 124 at armature 123 to ground over armature 149 and its front contact, and to connect the secondary Winding of the induction coil 124 in bridge with the trunk conductors 105 and 106 of the armatures 121 and 122.

'The relay 211 is energized over a previously traced circuit and operates its armature' 241 to complete a circuit for the slow-release relay 209. The armature 241 of the relay 211 is constructed so that, when it is released after i' being deenergized, it vibrates for a short interval of time, making lcontact with its front and back contacts. The slow-release vrelay 209 is energized to open the circuit of the re' lay 211 at armature 236,V and to open one point in the circuit of the relay 212 at armature. 237. The relay 211 is deenergized and the armaturev 241 is started to vibrate.

As a result of the engagement of the arma-- ture 241 with its back contact, a circuit is completed for the slovv-release relay 210. The relay 210 is energized to open another point in the circuit of the'relay 211 at armature 239, andato-prepare a circuit at armature 240 for the relay 212.

By the vibration of the armature 241, successive impulses of current are sent to the slow-release relays 209 and 210. The slowrelease relay 209 is thus maintained energized. The armature 241, in decreasing the amplitude of its vibra-tion, finally permanently opens the circuit of the relay 209. The relay 209 is then deenergized, after a short interval of time, to complete a circuit extending from ground b-y Way ot front contact and armature 164, conductor 195, armature 237 and its back contact, armature 240 and its front Contact, andrelay 212 to battery.

The relay 212 is energized to close a circuit for the slow-release relay 215 at armature 243, and to prepare a circuit for the relay 113 at armature 242. The slow-release relay 215 is energized, upon the deenergization of the slow-release relay 137. The slow-release revlayV 137, it will be remembered, is deenergized iat the end of the series of interruptionsconstituting the code of the station A-l.

The circuit `completed for relay 215 eX- tends from ground by Way of armature v199 and its back contact, conductor 196, armature 243,'andits front contact, armature 244 and -itsback contact, and slow-release relay 215 to battery. The slow-release relay 215 is energized to completel a circuit for the slow-release relay 214 at armature 246. The relay 214 is energized to complete a circuit that may be traced from ground by way of armature 199 'and itsback contact, conductor 196, armature 243 and its front contact, armature 245l and its front contact, front contact and armaturel 242,-' conductor 192, wiperv 145, bank Contact 174, and relay 113 to battery.

The relay 113 is energized to prepare a circuit .for the relay 116 at armature 198, to'place ground' upon the wiper 120 atl armature 130, and to complete a vcircuit at armature 129 that extends romground by way of i'ront contact andsaid-armature, armature 132 and its' back Contact, and stepping magnet 115 of the rotary switch S--l to battery.

V`The stepping magnet 115 is energized to complete a circuit for the slow-release relay 114at armature 131, and to adjust the pawl of the switch S-1 so that the wipers 117 to 120, inclusive, of this switch will be operatedone step when the magnet 115 is deenergized. The slow-release relay 114 is energized to openthe circuit ofthe stepping magnet 115 at armature 132.` The stepping magnet 115 immediately retracts its armature` to open the 4circuit of the slow-release relay 114-,and to advance'the wipers 117 to 120, inclusive, one stepv into engagement with their second set of bank contacts.

A circuit isnow completed that extends from ground by way oitl front contact and armature 130, wiper 120, `bank contact 172, conductor 184, armature 223 and its back contact, back contact of armature 226, conductor 187, and bell 126 to battery.V The bell is operated over this circuit and its sound causes the transmitter 125 to be `operated so as to `produce a corresponding sound in the loud speaker 110 at the dispatchers station A.

fTheslow-release relay 114 is deenergized, after a short interval of time, to again complete the circuit ofthe stepping magnet 115. The stepping magnetv 115 is energized to position its pa-wl and to complete a circuit forv the slow-release relay 114. The slow-release relay 114 is energized to open the circuit of the stepping magnet 115. The stepping magnet 115 is deenergized to open the circuit of the relay-114, and to advance the switch wipers 117 .to-120, inclusive, another step into 'engagement with their third set of bank contacts.r =As` al result of the operation of the wiper 120, the circuit of the bell 126 is opened and its'operation ceases, as does the operation of the loud speaker 110 at the central station. The intermittent operation of the stepping magnet 115 and theslow-release relay 114 bringsf fabout the continuous advancement of the switch wipers 117k to y120, inclusive.

This continues until the circuit of the relay 113 is opened. Y

When the switch wipers are brought into engagement with their fourth set of bank contacts, another circuit is completed for the bell 126 and the loud speaker 110 at the central station is again brought into operation. Upon the next movement of the switch Wipers, the circuit o the bell 126 is opened and the operation of the loud speaker 110 at the central station ceases. There will be no more operations of the bell 126 until the Wipers 117 to 120, inclusive,'have made half a revolution. f

It' will be seen that, during this operation of the kswitch wipers 117 to'120, inclusive, the bell 126 is operated twice. This produces a similar sound in the loud speaker 110. The dispatcher is thus given a code to inform him that stationy A-l has been selected by the operation of the selecting apparatus.

At this time, it will be well to note the operation occurring at the other stations that have not been selected by the code just sent to the selected'station A-l.

Inasmuch as the wipers of the rotary switches such as S, at all the stations .are in lengagement with their third set of bank"contacts and this third bank icontact is connected so as to actuate a relay,"such as 141, only at the station A-1, at all the other stations there will be a circuit completed that extends over a path such as the following: From ground by way of armature 149 and its front contact, armature 150 and its back-contact, wiper 146, third bank contact, armature 159 and its back contact, and relay 140 to battery. lThe relays,such as 140, at each station will be energized to establish a locking circuit for themselves at armatures, such as 158, to open the circuit of the line relays, such as 136, at ar1natures,such as 156, andV to open points in the impulsing circuits at armatures, such as 157. The operation of the relays, such as 140, at all the remaining stations thus prevents-any of the selecting equipment a these stations fromfbeing operated.'

As the circuit of the line relays, such as 136,.at all the remaining stations is opened by the operation of the relay 140, these line relays are deenergized. The result of the deenergization of these relays will be explained with reference to the rotary switch S. When the line relay 136 is deenergized, the circuit of the slow-release relay 138 is opened. This relay is deenergized to open one point in the circuit of the stepping magnet 143 and to open. one point in the circuit of the slow-release relayv 137 Returning now tothe operation of the switch S-l, the rotationl of the wipers 117 to 120, inclusive, continues and the code signal indicative of the station selection will be 'repeated until the dispatcherperforms some other operation.

Y Inasmuch asit has been assumed: thatthe dispatcher desires to bringr about the closure of the circuit interrupter C, he will novv operate his calling device104 in accordance with the digit 4. As a result of the operation of the calling device 104, four interruptions Will be produced in the circuitof the line relay 136. Y As a result of the retractions and attractions of the armature 149 of the relay 136, four impulses will be sent over a circuit extending from ground by Way of armature 149 and its back contact, back Contact and armature 157, armature 152 and itsV front contact, and stepping magnet 143 to battery. VA circuit in multiple with this one extends from ground by Way of armature 151 and its front contact, and slow-release relay 137 to battery.

The slow-release relay 137 is energized to open the circuit of the relay 142 at armature 150, and to remove ground from conductor 196 at armature 199. The relay 142 is deenergized to remove ground from the Wiper144 at armature V162, to open the circuit of the relay 111 at armature 163, to open the locking circuit of the slow-release relay 210 at armature 164, and to open the circuit of the relay 212 at this 'same armature.

As a result of the removal of ground from conductor196, thecircuit of the slow-release relay 215f is opened, as Well as the circuitof the relay 113. The slow-release relay 210 :is deenergized to open a point in the circuitof the relay 212 at armature 240, and'to prepare a point vin the circuit of the relay 211 at armature 239. The relay 212 is deenergized to open another point iny the .circuit of the sloW- release relay 215 andthe relay 113 at armaturel 243,]and to VOpen another point in the circuit ofthe relay 113 at armature 242.

The slow-release relay 215 is deenergized, after, a short interval of time, to open the circuitof the slow-release relay 214. The relay 214 is deenergized to open another point in the circuit ofthe relay 113. The relay'113 is deenergized to open apoint in the circuit of the relay 116 at armature 198, to open the circuit of the stepping magnet 115 at armar ture 129, and to remove ground from the Wiper 120 at armature 130. The .intermite tent operation of the stepping magnet 115 and the slow-release relay 114 of the rotary switch S-1 thus ceases(V .K

The stepping magnet143 is operated to ad# vance the Wipers V144 to 147, inclusive, intov engage-ment With the bank contact set which includes thevbank contacts 173 and 176 as a resultof the four impulses previously mentioned. The relay 137 is maintained energized during this intervaloftime.

A short interval of time afterthe termination ofthe operation of the armature 149, the slow-release relay 137 is deenergized. A circuit is thereupon completed that extends from ground` by Way of armature 149 and its front contact, armature 150 and its back contact, armature 161 and its front contact,`and relay 142 to battery. The relay 142 is ener-y gized. to connectground tov Wiper 144 at armature .162, tocoinpletea circuit for the relay 111 at armature 163, and to place ground upon conductor195 at armature 164. By the grounding of Wiper 1,44', a circuit is completed that .extends by Way of bank contact 173 with Which the Wiper is in engageu nient, conductor 191, armature 230 and its front contact, back contact and armature 221., conductor 188, and low-tone buzzer 127.

By the operation ofthe relay 142, the cir# cuit of the relay 111 is closed asstated before. The relay 111 is operated to complete a circuit for the primary Winding of the transformer 124 and to bridge the secondary Wind*-l ing of the transformer across the trunk conductors and 106. Y 127 is operated and a corresponding tone is reproduced by the loud speaker 110at `the central station. This tone informsthe dis patcher that the circuit interrupterCthat has been` selected is in an openposition." The' operation of the buzzer continues until-the circuit interrupter C is closed.`

The dispatcher, having ascertained that the circuitinterrupter C is in an open position,will Wait until he receives a signalfrom the high-tone buzzer 128 ,Which Will inform' him that the circuitinterrupter C atthe sei lected station has been operated. i In the eventthat the dispatcher received a high tone, he

would know that the circuit interrupter C that had been selected Was already in a closed condition,` and he would immediately restore the key Ktoxits normal position, thereby bringing about the release of the selecting apparatus in a manner that will be described fully hereinafter.V The circuit arrangement by Which a tone is given to the dispatcher immediately upon the selection to indicate the position ofthe selected apparatus unit is, of course, highly desirable.

1t Will be recalled that another result vof thel operation of relay 1421s that ground is connected` to conductor 195' that extends from ground by Way of armature 236 and its back contactnbackv contact and armature 239, and

relay 211 to battery. Therelay 211 is en# ergized to attract its armature 241, thereby, completing a circuit for theV slow-release re-V lay 209. The slow-release relay 209 is energizedto open Vthe circuit of the relay 211.

The relay211 isdeenergized to release the armature 241. The armature 241 then begins to vibrate and the slow-release `relay 210V is energized. The relay21() operates to coinplete a locking circuitfor itselfat armature 238, to openv another point in the circuit-of prepare a circuit at armature 240 for the relay212. -1 After ashort interval of time, the s1oW`` release'relay 209 is-deenergizedto complete the relay 211 at armature239, and to The low-tone buzzer. il

a circuit for the relay 212. lThe relay 212 is. energized to prepare a circuit for connecting ground to Wiper 145 at armature 242, and to complete a circuit for the relay 215 at arma- 555 ture 243. The relay 2,15 is energized to close the circuit of the slow-release relay 214. The relay 214 is operated to complete a circuit that extends from ground by way of armature 199 and its back contact, conductor 196, armature 243 and its front contact, armature 245 and its front contact, front contact and armature 242, conductor 192, wiper 145, bank contact 176, conductor 194, and relay 205 to battery. The relay 205 is energized to complete a circuit for the closing coil 207 of the circuitinterrupter C. The circuit interrupter C is immediately closed toclose any desired power circuit at the station.

As a result of the operation of the auxiliary switch 235 of the circuit interrupter C, the circuit of the closing coil 207 is opened. The breaker is then maintained in closed position by the usual latching mechanism. As a result of the operation ofthe auxiliary switch 234, the circuit of the relay 204 is opened and this relay is deenergized to open the circuit of the low-tone buzzer 127 at armature 230, to complete a circuit for the hightone buzzer 128 at the back contact of this armature, and to complete a circuit atarmature 229 extending from ground by way of back contact and said armature, front contact and armature 231,v and relay 213 to battery.

The relay 213 is energized to open the circuit of the slow-release relay 215 at armature 244, and to establish a locking circuit for itself at the front contact of this armature, front contact and armature 243, conductor 196 to ground over armature 199. The slow-release relay 215 is deenergized, after a shortinterval of time, to open the circuit of the slow-release relay 214. The, relay 214 iis deenergized to open the circuit of the relay ,205. The relay 205 is deenergized to open another point in the circuit of the closing coil 207.

The'circuit over which the high-tone .buzzer is operated extends from ground by way of front contact and armature 162, wiper 144,

230 and its back contact, conductor 189, and buzzer 128 to battery. The sound produced by the operation of the buzzer 128 is reproduced by the loud speaker 110, and the dispatcher is thereby informed that the circuit interrupter C at the selected station hasv $5 at all the stations will thereby be reversed.

bank contact 173, conductor 191, armature `VAs a result of this operation, at station A-1, the circuit `of the slow-release relay 139 is opened. After a short interval of time, the slow-release relay 139 is deenergized to open the circuit of the line relay 136 at armature 154, to open the locking circuit of the relay 141 at armature 155, to complete a lcircuit at the back contact of this armature that extends from ground by way of the bank contact with which wiper 147 isin engagement, said wiper, back contact and armature 165, and stepping magnet 143 to battery and to complete a circuit that extends from ground by way of back contact and armature 153, bank contact with which wiper 119 is in engagement, armature 132 and its back contact, and stepping magnet 115 to battery.

The relay 142 is deenergized to open the circuit of the high-tone buzzer 128 at armature 162, to open the circuit of the relay 11.1 at armature 163, and to open the circuits of the relays 210 and 212 at armature 164. rIhe relay 210 is deenergized to prepare a circuit for the relay 211 and to open another point in the circuit of the relay 212. The relay 212 is deenergized to open the circuit of the relay 213. The relay 213 is deenergizedv to prepare a circuit for thev relay 215.

The relay 111 is deenergized to disconnect thetransmitter 125. The line relay 136 is deenergized to open the circuit of the slowrelease relay 138. `After the line relay 136 is deenergized and before the slow-release relay 138 is deenergized, a circuit is completed Jfor the relay 137 V from ground, back contact and armature 149, Vback contact and armature 157 ,.armature 151 andrelay 137, battery to ground. The relay 137y is energized to remove ground from conductor196. The slow-release relay 138 is deenergized, after a short intervalof time, to open the circuit of the relay 137, which is also deenergized. Y

-The stepping magnet 143 interrupts its own circuit and operates as va buzzer to advance the switch-wipers 144 to 147, inclusive, ofthe rotary switch S .to their normal position. The stepping magnet 115 and the relay 114 of the rotary switch S-l are intermittently operated to cause the wipers 117 to 120, inclusive, to be advanced to their normal position. In this manner, all the selecting apparatus at the station is released. The release of the selecting apparatus at the other stations -occurs in substantially the same manner, following the deenergization of the slow-release relays, such as 139, in these stations.

It will now be assumed that the dispatcher desires to ascertain the gate opening of the turbine at the station A-1. In order to accomplish this result, the dispatcher will operate his calling device in accordance with the code 2001. The operation of the selecting equipment responsive to the first digit is effective to select the station A*1 in the same manner as previously described. The operation of the selecting switch S responsive to the second digit 0 isto advance the switch Wipers 144 to 147, inclusive, into engagement with their thirteenth set of bankl contacts. As these contacts are. not connected, this operation is Without particular function.

This operation of the selecting apparatus responsive to the next digit brings the switch Wipers 144 to 147, inclusive, into engagement With their twenty-third .set of bank contacts. As these bankcontacts are not connected, this operation is also Without function.

By the operation of the calling device in accordance with the last digit, one interruption is produced in the circuit'of the line relay 136 and the stepping magnet 143 is operated to advance theswitch Wipers 144 to 147, inclusive, one step into engagement with the twenty-fourth set of bank contacts. y The slow-release relay 137 is ,energized over a circuit in multiple with the stepping magnet 143. A short interval of` time after the attraction of the armature 149, following this digit, the slow-release relay 137 is deenergized. A circuit vis thereby completed that extends from ground by Way of armature 149 and its front contact, armature l150 and its back contact, armature 161` and its front contact, and relay 142 to battery.

The relay 142 is energized v to connect ground to Wiper 144 at armature 162, to complete a circuit for the relay 111 at armature 163, and to place ground upon conductor 195 at armature 164. rIhe `relay 111'is` energized to connect the transmitter 125 to the trunk conductors 105 and 106. The grounding of Wiper 144 is Without function.

The connection of ground to conductor 195 causes the operation of the relay 211. The relay 211 is energized i'o complete a circuit for the relay 209. The relay 209 is energized to open the circuit of the relay 211. The relay 211 is deenergized to cause the operation of the relay 210. The relay 210 in energized to establish a locking circuit for itself and to prepare a circuit for the relay 212. The relay 209 is deenergized, after'a short vinterval of time, to complete a circuit for the relay 212.

The. relay 212 is energized to prepare a circuit for the relay 202 at armature 242, and to complete `a circuitl at armature 243 that extends from ground bynway` of armature 199 and its back contact, conductor 196, armature 243 and its front contact, armature 244 and its back contact, and slow-release relay 215 to battery. The slow-release relay 215 is energized to complete a circuit for the relay 214. -Y

The relay 214 is energized to complete a circuit that extends from ground by Way of armature v199 and its back contact, conductor 196,' armature 243 and its front contact, armature 245 and its front contact, front contact and armature 242, conductor 192, Wiper 145, bank contact 179, conductor 186 and relay 202 to battery.

The relay 202 is energized to open'a point in the circuit of the code bell 126 at armature 226, to complete a circuit for the relay 200 at armature 225, and to place battery upon the Wiper 218 at armature 224. The relay 200 is energized to prepare a circuit for the buzzer 127 at armature 221, and to complete a circuit at armature 220 that eX- tends from ground by Way of said armature and its front contact, conductor 183, and relay 113 to battery.

The relay 113 is energized to place ground upon theiviper 117 at armature 198, to place ground upon the Wiper 120 atarmature 130, and to complete a circuit at armature 129 for the stepping magnet 115. The stepping magnet 115 is energized to adjust its paWl and to complete a circuit for the slow-release relay 114 at armature 131. The stepping magnet 115 and the slow-release relay 114 are intermittently operated to advance the Wipers 117 and 120.

When the wipers are brought into engagement With the bank contact set Which includes the bank contact 112', there is a circuit completed that` extends from ground by Way of armature 198 and its front contact, armature 133 and its back contact, Wiper 117, bank contact 112, conductor 180, front contact and armature 221,- conductor 188, and buzzer 127 to battery. The buzzer 127 is operated and its tone is reproduced by the loud speaker 110 at the central station.

Vlhcn the Wipers 117 to 120inclusive, of

the rotarysvvitchS-l are broughtinto engagement with their seventh set of bank contacts, the circuit for the buzzer 127 is opened and its operation ceases. When the Wipers arer brought into engagement with their eighth set of bank contacts, a circuit is again completed for the buzzer 127.

grcund from the Wiper 117. Consequently,`

during the subsequent advancement of the Wipers 117 to^120, inclusive, during this half revolution, the buzzer is ynot operated. By the code that is sent out from the buzzer 127 that iscontrolled by the positionof the con- The buzzer `is intermittently operated until the Wipers iso tact-making member 218 of the gate switch, the dispatcher is informed of the gate opening.

" vlVhenthe'wipers 117 to 120, inclusive, are brought into engagement with their twentyfiftli set of bank cont-acts, a circuit is completed extending from ground by way of the twenty-fifth bank contact of wiper 118, front Contact and armature 184, and resistor 108 to battery. rlhis circuit serves to shunt the relay 116 and it is deenergized. The deenergization of the relay 116 serves to prepare another circuit in order that the code signal representing the gate opening will be repeated upon the next operation of the switch S-1. After the dispatcher has properly received the position of the gate opening, he may bring about the release of the apparatus in the same manner as before described by reiter-ing the key K to normal.

I When certain apparatus in the substations is operated, it is desirable that they be locked out so that the dispatcher cannot reclose the device to its original position without specifically noting that it has been operated by the automatic devices. The circuit interrupter C-l at the station iti-1 is a device of this kind. Y

It will be assumed that the circuit interruptor @-1 is closed and that the overload relay 256 is operated by reason of a shortcircuitl on the power line 290. The operation of 'the relay 25S brings about the closure of a circuit for the opening coil 259 of the circuit interrupter C-l at the switch 270 and the closure of a circuit for the relay 219 at the spring 271.

By the operation of the auxiliary switch 274 ofthe circuit interrupter (1 -1, the eircui't of the relay is completed. The relay 253 is energized and operates to attract the armature 264 to prepare a. circuit for the low-tone buzzer. to further open a circuit for the relay 213 at armature 266, and to momentarily complete a circuit that extends from ground by way of .armature 199 and its back contact, conductor 196, armature 243 and its'back contact, normally closed springs controlled by armatme 265, said armature, and relay 251 to battery.

The relays 250 and 251 have their armatures mechanically latched so that, even when the relay 250 is deenergized, the armature 260 is maintained in connection with its front contact by the lat-ching member carried by the armature 261. The relay 251 isY momentarily energized toattract its armature 261. thereby permitting the armature 20,0 to restore to normal. In this manner, a point in the circuit of the relay 254 is opened. The relay 254 controls the circuit of the closing coil 258 of the circuit interrupter @-1. Consequently7 this circuit interrupter cannot be closed until the relay 250is energized. The relay 219 is energized as a result of the operation of the relay 256. The relay 219 operates to establish a locking circuit for itself at armature 263 and the left armature contact 148 to ground, and to complete a circuit at 'armature 262 that extends from ground'by way of said armature and its front contact, and relay 203 to battery. VThe relay 203 is energized to connect ground to conductor 188 at? armature 227, .and to connect ground to conductor 190 at armature 228.

The grounding of conductork 190 brings about the energization of the relay 111. The

relay 111 operates to connect the transmitter 125 inthe circuit acrossthe trunk conductors i 105 and 106. 'The grounding of conductor 188 brings the buzzer 127 into operation. A tone is thus produced by the loudspeaker 1,10 at the dispatchersstation'to inform him that an operation has occurred at one of the stations. If the buzzers are diferently pitched at each station, the dispatcher will know immediately what station the opera` tion is in The dispatcher will then operate the key K and the calling device 104 in acis operated. He will be able to ascertain :.100

this by reason of the fact that the circuit interrupter that has been operated by the operation of the automatic devices will bepositioned different than noted on his chart or memorandum.

After ascertaining the` position of the' circuit interrupter C-l by operating his calling device so that the wipers 144 to 147, inclusive, are brought into engagement with the bank contact set that includes the bank contact 194', the dispatcher will operate his calling device in accordance with the code that will bring the wipers 144 to 147, inclusive, into engagement with the bank contact set that includes the bank contact 177. The relay 142 will then be energized, as before, to bring about the operation of the relay 111, the connection of ground to wiper 144, and the connection of ground to conductor 195. Y

By the connection of ground to wiper 144, a circuit is completed for the ibuzzer 127. This buzzer again informs the dispatcher of the position of the circuit interrupter C-1. By the grounding of conductor 195, the relays 209, 210, 211, 212, 214 and 215 operate as before.

When the relay 214 is energized, a circuit is completed extending from ground by way of armature 199 and its back contact, conductor 196, armature 243 and its front conist . energized to By the operation of the relay 250, the circuit interrupter is no longer locked out and the dispatcher may operate the circuit interrupter 0 1, in the same manner as the cirl cuit interrupter C was operated, by dialing its code after restoring the key K to normal and reoperating it. By the restoration of they key K, the selecting equipment is released in the same manner as before described. To close the circuit interrupter C-l, the dispatcher Will operate his calling device in accordance With the code of this interrupter. These operations Will be obvious from the preceding description.

The alarm signal, the operation of which Was described in the foregoing description, is operated When the circuit interrupters are operated under the control of automatic devices in the various stations, and the attention of the dispatcher is thus called to the operation of the automatic equipment in any particular station. Y

Telephone communication may be carried on between any one of the stations and the central station in the usual manner. The stations may be selectively signalled by definite codes.

In the event that the operator at the central station desires to communicate with any of the substations, it is only necessary for him to close the key 198 which connects the ringing current through the line to operate the bell ringer at the other station equivalent to the ringer 108 and to lift the receiver .102, thereby closin a circuit for the transmitter 101 through t e transformer 100 to the signalling lines 105 and 106. '.Ihe operator at the distant stations, upon being attracted by the ringing current, Will lift his receiver 1 69 to Complete telephone communication circuit between the tWo stations. Thereafter, communication may be carried on in the usual manner.

My invention is not limited to the particular arrangement of the apparatus described, but may be variously modified Without departing from the spirit and sc ope thereof, as set forth in the appended claims.

I claim as my invention:

1. In a control system, the combination With a iirst and second station, and apparatus units in the second station, of a latching device associated vvith one of the units, a selecting device at the second station, means for operating the selecting device to select the unit With Which the latching device is associated, means controlled by suoli selection for operating the latching device Without operating said unit, means for releasing the prepare a circuit for the relayv selecting device, means for again operating it to select the unit, and means including circuit connections controlled by said latching device and responsive to such selection for operating the selected unit. n

' 2. In a supervisory control system, a irst station, a second station, apparatus units at said second station, an audible signalling device at said first station, .automatic means for operating said apparatus units, means responsive to tlijeautomatic operation of any one of said apparatus units for operatingA said audible signalling device, a selector atV said second station only, means including a calling device for transmitting a series of impulses from said rst to said second station, means responsive to said series of impulses for operating said selector device to select any one of said apparatus units and for conditioning said unit for operation, means responsive to said selection for transmitting audible signals of predetermined nature to said iirst station indicative of the condition of said unit, means including the calling device for transmitting a series of impulses of different numberfrom said rststation to said secondstation tooperate said selected apparatus unit Vand means for transmitting audible signals of different predetermined nature from said second stationto said first station indicative of the operated condition ofi said unit. A

' 3. In a supervisory control system, a iirst station, a second station, apparatusunits at said second station,j anv audible signalling device vat said lirst station, automatic means for operating said apparatus units, means responsive to the automatic operation of any one of said apparatus units for operating said signalling device,'a selector at said second station, means including a calling device for transmittinga predetermined number of impulses from said iirstto said second station, means responsive to the said predetermined number of impulses-for operating said selector device to select anyone of said apparatus units and for conditioning said unit for operation, means responsive to said selection for transmitting Yaudible signals of one tone to said iirst station indicative of the condition of said selected unit, means including the calling devicey for transmitting a different number of impulses from said first station to said second station-to operate said selected apparatus unit and means for transmitting audible signals of another tone from said second station to said `first station indicative of the operated condition of said unit.

1. In combination, a central station, a remote station, a circuit connecting said stations, a plurality of devices at the remote station movableto tvvo positions, a pair of devicesat the remote station associated With said circuit for impressing current variationsof dierent character on said circuit, an

audible signaldevice at the central station responsive to the current variations of different character, selecting means at the re-v mote station controlled from the central station over said circuit for selecting one of said first mentioned devices, a circuit closed by the selecting means and including one or the other of the second mentioned devices depending upon the position of the selected device, means including said selecting means for operating the first mentioned devices from the central station, means whereby the first mentioned devices may be operated at the remote station independent of the central station, means whereby upon such operation one of the second mentioned devices is rendered active to continuously impress current variations on said iirst circuit independent of the selecting means, and means including said selecting means for discontinuing such activity of said one second mentioned device.

5. In a control system, the combination with a first station and a plurality of remote stations, of a selecting device in each of the remote stations, apparatus units in the remote stations, a line connecting all of said stations, a calling device at Hirst station for transmitting impulses over said line to select Aa ldesired remote station, means at the remote station responsive to another operation of the calling device for causing the selecting device to select a desired apparatus unit for operation, operating means for the selected unit rendered eifective in responserto the selecting operation, means operative upon the subsequent operation of' the selecting device for causing the operating means to operate the selected unit, and audible tone-producing means common to all of said apparatus units in each remote station, responsive successively to the selection of the station, selection of an apparatus unit and the `operation of the selected unit, for transmitting audible signals to the first station indicative lof station selected and the position of the apparatus unit.

6. In a control system, the combination with a first station and a plurality of remote stations, of a selecting device in each of the remote stations, apparatus units in the remote stations, a line connecting all of said stations, a calling device' at first station for transmitting impulses over said line to select a desired remote station, means at the remote station responsive to another operation of the calling device for causing the selecting device to select a desired apparatus unit for operation, operating means for the selected imit rendered effective in response to the selecting operation, means controlled from Vthe 'first 'station for releasing the selecting device, means operative in response to the subsequent operation of the selecting device for effecting the operation of the operating means, audible-tone transmitting means `fat each remote station, and means at the selected station responsive to the selecting device and the position of the selected apparatus unit for causing the audible-tone transmitting means to transmit audible signals to the first THOMAS u. WHITE.

this 15th day of June 1925. 

